In line with the advancement and popularization of computer technologies, content (books, comics, records, movies, broadcastings, newspapers, or the like) of general commercial transaction produced, kept, and managed in an analog form has been mostly digitalized.
The characteristics and advantages of digital content that quality of the original digital content is free of damage although digital content is infinitely used, digital content is easy to copy and modify, and easy to transfer and distribute within a short time using a ultra high-speed communication network although it is a large amount of work, make analog works digitalized at high speed.
However, the advantages of digital content also act as a factor violating the rights and benefits of the original author. Specifically, since a copy is identical to the original, the intent to purchase the original may be dampened and since the original is simply modified and duplicated without the consent of the author, works may be easily plagiarized. In addition, the ease in transfer and distribution makes unauthorized duplicates instantly spread through the Internet, incapacitating even legal controls.
Such negative factors may demoralize authors to weaken their intent for creating works, and thus cause hesitation of digitalization. Therefore, a technical protecting device capable of effectively managing copyright, while sufficiently saving the digital advantages of digital content, is required.
In order to protect the benefits and rights of digital content, a technique of applying DRM to digital content has emerged, and various DRM schemes have also been used.
Here, the term DRM refers to a series of techniques of preventing illegal reproduction or duplication, protecting the rights and benefits of respective subjects (content creator, a distribution dealer, a distributor, a user, a copyright holder, and the like) participating in a life cycle (i.e., creation, processing, distribution, and consumption of content) of digital content, and supporting charging and payment according to the use of digital content.
Thus, a server that provides digital content using a DRM scheme encrypts digital content and transmits the same, and a license management server transmits a license to an authorized user so that only the authorized user can play and output the digital content. Here, the license includes a digital content encryption key used for decoding the digital content, digital content permission information as information regarding the use of the digital content, and the like.
Meanwhile, recently, terminal apparatuses equipped with an operating system have become prevalent, and typical terminal apparatuses include iPhone equipped with an iOS operating system provided by Apple Inc. and Android phone equipped with an android operating system provided by Google Inc., and the like.
In supporting multimedia content encrypted based on DRM, a decoding module scheme used in a general personal computer (PC) environment may not be applied to the terminal apparatuses equipped with such operating systems. Thus, a dedicated DRM decoding module is directly installed in operating systems of the terminal apparatuses equipped with such operating systems. A typical example is FairPlay of Apple Inc.
However, in case of the dedicated DRM decoding module directly installed in the operating systems, it was difficult to alter a source code of an installed multimedia device player or add a function in terms of characteristics of the operating systems.
Thus, conventionally, a scheme of providing a local web server module to a terminal apparatus equipped with an operating system and allowing the terminal apparatus equipped with the operating system, without a dedicated DRM decoding module, to play multimedia content encrypted based on DRM has been proposed.
In this case, however, if any other application accesses a URL in which multimedia content encrypted based on DRM can be played, there was a security problem that the original of the multimedia content encrypted based on DRM may be leaked.